This invention relates to the packaging of compressible materials such as foam and spring assemblies used in the manufacture of mattresses and the like, and is more particularly directed to an apparatus for packaging such compressible materials into a roll.
Conventional packaging and transportation of compressible materials such as finished mattresses, as well as foam or spring assemblies used in the manufacture of mattress products, generally involves handling of the materials in an uncompressed state. As such, the shipping and storage of the materials requires much more space than would be required if the materials were provided in a compressed state. To improve the efficiency of shipping and storage, foam mattress cores have been packaged in a compressed state by flattening the foam and sealing it in an evacuated bag. See, for example, U.S. Pat. No. 4,711,067 to Magni. This method of packaging foam cores, however, is not useful in packaging spring assemblies. In addition, storage and transportation efficiencies of the foam could be further improved by packaging the flattened cores into a tight roll.
Roll packing generally involves winding-up a desired material to form a roll and then securing the roll to prevent uncoiling of the roll during handling. In the case of compressible materials such as mattresses and foam or spring cores, it is often desired to compress the materials during the roll packing process to obtain a more dense and compact roll. Various devices have been used to achieve compression of roll packed materials. U.S. Pat. No. 3,927,504 to Forrister discloses an apparatus for rolling resilient foamed sheet material without the use of a mandrel. This machine is not useful for packaging spring assemblies and does not have the capability to package multiple units of a compressible material into a large roll. The device further does not provide for packaging a compressible material with a barrier layer between successive turns of the roll, which barrier layer is desirable to prevent adhesion between successive layers of foam.
Some roll packing systems further include a mandrel for facilitating the winding of the material. For example, U.S. Pat. No. 2,114,008 to Wunderlich discloses a spring packing machine having a radially collapsible arbor for use in roll packing spring assemblies. A barrier layer between successive turns of the roll keeps the spring assemblies separate and permits easy removal of a single assembly from the roll. However, this machine is not useful for roll packing foam material due to the presence of a pressure bar 50, between belt 15 and the collapsible arbor, which would tend to snag a compressed foam as it passed beneath. The disclosed machine also has other drawbacks. For example, to remove a finished roll, the arbor must be removed from the machine and collars must be adjusted to collapse the arbor so that the roll can be taken off the arbor. The arbor must then be replaced in the machine before another roll can be formed. Operation of the machine is thus very labor intensive and ergonomically inefficient.
There is thus a need for a simple apparatus capable of roll packing multiple units of various compressible materials, such as foam mattress cores, mattress spring assemblies, and finished mattress products and which is ergonomically efficient and is capable of providing a barrier layer between successive turns of a formed roll.
The present invention provides a simple machine for roll packing a variety of compressible materials such as foam cores, spring assemblies, and fiber materials used in the manufacture of mattress products, as well as finished mattresses themselves. The machine has a radially collapsible mandrel that permits finished roll packed materials to be easily removed from the machine by sliding the roll off of the mandrel. This radially collapsible mandrel permits rolled materials to be removed without any telescoping or tearing of the materials which is usually caused by binding of the roll packed material on the mandrel. The machine of the present invention is especially useful in roll packing foam materials which are highly susceptible to binding against a mandrel. The simplicity of design of the machine of the present invention further permits use in roll packing practically any compressible material, even materials as diverse as coiled spring assemblies for mattresses and foam cores.
In accordance with the present invention, an apparatus is provided having a radially collapsible mandrel for winding compressible materials to be roll packed. A feed table is provided upstream of the mandrel to support and direct the compressible material to the mandrel. A packing material dispenser is further provided proximate the mandrel to feed packing material to the mandrel with the compressible material. A compression roller associated with the mandrel is used to compress in-fed compressible materials between the compression roller and the mandrel as the material is being wound upon the mandrel. The compression roller is adjustable to vary the spacing between the mandrel and the compression roller so that the amount of compression for the in-fed materials can be varied accordingly. In one exemplary embodiment, a pneumatic cylinder is used to adjust the position of the compression roller relative to the mandrel. The mandrel is driven at one end by a driving mechanism including, for example, a motor and a gearbox, and has a bearing plate at the opposite end. The bearing plate is movable away from the end of the mandrel so that a finished roll of material can be easily pushed off of the mandrel after it has been collapsed. In another exemplary embodiment, the apparatus includes a stripper bar associated with the mandrel to facilitate the removal of finished rolls from the mandrel, and further includes a roll handler for receiving the finished roll as it is pushed off the mandrel.
In further accordance with the present invention, a method for roll packing various compressible materials includes the steps of providing a collapsible mandrel and a compression roller, directing in-fed compressible materials between the mandrel and compression roller, adjusting the spacing between the mandrel and compression roller, winding the compressible material around the mandrel, stopping the mandrel when a desired amount of in-fed material has been wound upon the mandrel, collapsing the mandrel, and removing the roll packed material from the mandrel. A method for roll packing foam materials, in particular, in accordance with the present invention is disclosed in U.S. patent application Ser. No. 09/986,227, entitled xe2x80x9cMethod for Roll Packing Foam Cores,xe2x80x9d filed on even date herewith, assigned to the assignee of this application, and incorporated by reference herein in its entirety.
Accordingly, the invention provides a simple apparatus and method for roll packing a variety of compressible materials and which has a collapsible mandrel that facilitates the easy removal of finished rolls without tearing, telescoping, or otherwise damaging the roll packed material. These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and description.